1. Technical Field
The present invention relates to a printer that is communicably connected over a network to a host computer and operates according to commands and data sent from the host computer, to a host computer, to a printing system, and to a control method for the printing system.
2. Related Art
On-line systems that are communicably connected over a network to a host computer are known. In such on-line systems data is typically exchanged between a host computer and a terminal device that is located remotely from the host computer. In response to requests from the remotely located terminal devices, such as automatic teller machines (ATM) in bank branches, cash dispensers, and POS terminals in retail stores, for example, the host computer executes a particular transaction process using the data passed from the terminal device and returns the result of the process to the terminal device, and the terminal device then outputs the result of the transaction process.
Japanese Unexamined Patent Appl. Pub. JP-A-2005-222310 teaches a POS system 1 including a POS terminal computer 60, a printer 10, and a POS server 70. The POS terminal computer 60 computes the total of a sales transaction based on product information input by an operator. The printer 10 is connected to the POS terminal computer 60 and executes processes related to printing sales receipts R and reward cards P that record reward points awarded for product purchases, for example. The POS server 70 is connected to the POS terminal computer 60 over a network 75. This POS system 1 provides a reward points system as part of customer services designed to stimulate customer desire to buy more products and to secure repeat business from a regular customer base by recording points earned according to the total purchase amount or number of purchases, for example, on a reward card or membership card carried by the customer, and then provides certain benefits to the customer when the accumulated number of points reaches a particular level.
In a POS system 1 such as this, the plural POS terminal computers 60 and printers 10 are each managed by the same operator. In other types of on-line systems, however, the printer 10 is not managed by a local terminal device as it is in a POS system, and the printer 10 is instead directly controlled by a server (host computer) located in a remote location. If the operator is located near the printer and not the server in such a system, the operator cannot determine if the server is operating normally when the system is being used.
An example of a such an arrangement is when a subsystem other than the POS system 1 is also deployed in a store, and a printer other than the POS terminal printer 10 is used at the operator location. In this arrangement the subsystem server instructs the subsystem printer to print a ticket or coupon, for example, in conjunction with an operation of the POS system 1 operation, and the subsystem printer prints the tickets or coupons only when so instructed by the subsystem server. In this example the operator does not know when a ticket or coupon will be issued by the subsystem printer. Therefore, if the entire server or an application that runs on the subsystem server crashes or hangs, or a communication error occurs in the connection between the server and printer, the operator has no way of immediately knowing that there is a problem with the server or connection. As a result, the ticket or coupon will not be issued as required at the appropriate timing and the operator will proceed with the transaction while remaining unaware that a problem has occurred.